b2250e5dbb
This is in preparation for https://codereview.webrtc.org/2517173004/, which needs some updates of downstream dependencies. This cl adds the target to api/BUILD.gn, creates the directory api/video, and a single harmless include file there. BUG=webrtc:5880 Review-Url: https://codereview.webrtc.org/2546723003 Cr-Commit-Position: refs/heads/master@{#15385}